The effect of continuing versus withholding angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers on mortality and major adverse cardiovascular events in hypertensive patients undergoing elective non-cardiac surgery: study protocol for a multi-centric open-label randomised controlled trial.

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs) are commonly prescribed to patients with hypertension. These drugs are cardioprotective in addition to their blood pressure-lowering effects. However, it is debatable whether hypertensive patients who present for non-cardiac surgery should continue or discontinue these drugs preoperatively. Continuing the drugs entails the risk of perioperative refractory hypotension and/or angioneurotic oedema, while discontinuing the drugs entails the risk of rebound hypertension and myocardial ischaemia. The aim of this study is to evaluate the effect of continuation vs withholding of ACEIs/ARBs on mortality and other major outcomes in hypertensive patients undergoing elective non-cardiac surgery.

METHODS

The continuing vs withholding of ACEIs/ARBs in patients undergoing non-cardiac surgery is a prospective, multi-centric, open-label randomised controlled trial. Two thousand one hundred hypertensive patients receiving ACEIs/ARBs and planned for elective non-cardiac surgery will be enrolled. They will be randomised to either continue the ACEIs/ARBs including on the day of surgery (group A) or to withhold it 24-36 h before surgery (group B). The primary endpoint will be the difference in the composite outcome of all-cause in-hospital/30-day mortality and major adverse cardiovascular and non-cardiovascular events. Secondary endpoints will be to evaluate the differences in perioperative hypotension, angioneurotic oedema, myocardial injury, ICU and hospital stay. The impact of the continuation vs withholding of the ACEIs/ARBs on the incidence of case cancellation will also be studied.

DISCUSSION

The results of this trial should provide sufficient evidence on whether to continue or withhold ACEIs/ARBs before major non-cardiac surgery.

TRIAL REGISTRATION

Clinical Trials Registry of India CTRI/2021/01/030199. Registered on 4 January 2021.